sine.hh

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
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/*   This file is part of the C++-library RFFGen.                              */
/*   Copyright 2015 Lars Lubkoll                                               */
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#ifndef RFFGEN_CMATH_SINE_HH
#define RFFGEN_CMATH_SINE_HH

#include <cmath>
#include "../Util/base.hh"
#include "../Util/chainer.hh"

namespace RFFGen
{
  namespace CMath
  {
    struct Sin : Base , Chainer<Sin>
    {
      using Chainer<Sin>::operator ();

      explicit Sin(double x=0)
      {
        update(x);
      }

      void update(double x)
      {
        sinx = ::sin(x);
        cosx = ::cos(x);
      }

      double d0() const noexcept { return sinx; }

      template < int = -1 >
      double d1(double dx=1.) const { return cosx*dx; }

      template < int = -1 , int = -1 >
      double d2(double dx=1., double dy=1.) const { return -sinx*dx*dy; }

      template < int = -1 , int = -1 , int = -1>
      double d3(double dx=1., double dy=1., double dz=1.) const { return -cosx*dx*dy*dz; }

    private:
      double sinx, cosx;
    };

    template <class Function, class = std::enable_if_t<std::is_base_of<Base,Function>::value> >
    auto sin(const Function& f)
    {
      return Sin()(f);
    }
  }
}

#endif // RFFGEN_CMATH_SINE_HH